Corona discharge protective device



March 24, 1942. J TRANSTROM 2,277,187

06mm DISCHARGE PROTECTIVE DEVICE Filed Oct. 5, 1938 Fig. 4

en Wane/ram, IN V EN mR.

A TTORNEY.

Patented Mar. 24, 1942 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to a corona discharge protective device,particularly useful in electrical demonstrations with the human body forresearch, classroom lectures and entertainment.

Demonstrations of corona discharges from the tips of ones fingers orthumbs causes considerable pain therein, also burns the same.

The general object of the invention is to provide a device of thecharacter stated which may be worn on ones fingers or thumbs to protectthe same against pain and from being burnt, when a corona discharge isdischarged therefrom during electrical demonstrations as aforesaid.

Other objects and advantages will appear hereinafter.

The invention is illustrated in the annexed drawing which forms a partof this specification and in which,

Fig. 1 is a perspective View of a man giving a demonstration of anelectrical corona discharge from the tips of his fingers, on which areplaced my protective device to prevent burning of the fingers.

Fig. 2 is a perspective of the high frequency oscillatory transformerwith a plate on the top thereof and connected thereto, on which plate aman stands for giving a corona discharge exhibition,

Fig. 3 is a perspective of a human hand on the finger tips of which areplaced the protective caps of my invention.

Fig. 4 is a perspective of one of the protective finger tip caps of myinvention.

Fig. 5 is a perspective of a modification of my finger tip cap.

Fig. 6 is a perspective of another modification of my finger tip cap.

Fig. 7 is a perspective of a modification of my invention showing astick of wood with its lower portion wrapped with a metal foil conductorand held by a human hand.

Fig. 8 is a side View of another modification of my protective fingercap.

Referring more particularly to the drawing in which corresponding partsare designated by the same reference characters in all of the figures, Idesignates a cap, of metal or other suitable conducting material, whichis closed at its outer end by an end wall 2. On one or more of thedigits of the hands of the person giving a corona dischargedemonstration are placed one or more of the caps l as illustrated inFigs. 1 and 3 of the drawing.

Apparatus is provided for sending an oscillatory electrical currentthrough the body of a person giving a demonstration of an electricalcorona discharge from the tips of his fingers and thumbs through myprotective cap I, which apparatus comprises a drum 3 of high-insulationmaterial, a high frequency oscillation transformer I wound on said drumand a plate 5, of metal on other suitable insulating material, supportedon one end wall 6 of said drum, said plate being connected at I to theremote end of the secondary coil 8 of the transformer 4, and the ends ofthe primary coil 9 being connected to leads in and II respectively whichlead from any suitable high frequency generator (not shown). The drum 3is placed with its end, opposite its end wall 6, resting upon the fioorand said end wall and plate 5 uppermost, as shown in Figs. 1 and 2, sothat a person indicated l2 may stand on said plate with his feet bare orwith metal-soled shoes on his bare feet, as shown in Fig. 1, to makegood electrical contact between said person and said plate.

The operation, uses and advantages of my invention are as follows:

The person l2 giving the corona discharge demonstration, with myprotective device on his fingers and thumbs, stands, with his bare feetor with metal-soled shoes on his bare feet, on the plate 5, while ahigh-frequency oscillatory electric current is conducted from a highfrequency generator through leads l0 and H, through the primary coil 9of transformer 4, through secondary coil 8 of said transformer and plate5, and then through said persons body, from which said electric currentis given off in a corona discharge from my protective device on saidpersons finger tips, as illustrated in Fig. l, which device preventsburning of the finger tips of said person.

Normally the corona discharge from the cap I is practically a whiteflame, but flames of different colors may be discharged from the cap Iby applying difierent chemicals to the surface of said cap. For examplestrontium chloride applied to said caps will cause the corona dischargeto produce a dark red flame, lithium chloride will produce a bright redflame, barium chloride a green flame, and copper chloride a blue flame.

The modification of my protective cap 13 shown in Fig. 5 is made offabric and when it is used it is wet in a conducting liquid to conductthe electric current from the tips of the fingers and give QII Saidcurrent in a corona discharge.

The modification of my protective cap 14 shown in Fig, 6 is open at itsouter end as indicated at i5.

In the modification of my invention shown in Fig. 7 a stick l6 of woodor other inflammable material is Wrapped or enclosed for a portion ofits length from one end with a metal foil or other conducting materialIT. The person demonstrating my invention, while standing upon the plate5, grasps with one hand l8 the portion of the stick I6 which is wrappedby the conductor I1, and the current passing from said hand through saidconductor is discharged from the end of said conductor into the stick 16which ignites said stick and causes it to burn rapidly with a brightflame, the current finally discharging in a corona at the remote end ofthe stick.

The modification of my protective cap 19 is made of metal bead cloth 20.

In this specification and the annexed drawing I disclose my invention inthe form which I consider the best, but I do not limit my invention tosuch form, because it may be embodied in other forms, and it is to beunderstood that in and by the claims of this specification I intend toprotect my invention in whatever form it may be embodied.

I claim:

1. Apparatus as disclosed including means for introducing a charge ofelectricity into a human body, and a fabric conductor cap placed on thetip of a digit of the hands of said body to protect said digit againstthe objectionable effects of corona discharge of said electricitythrough said digit.

2. Apparatus as disclosed including means for introducing a charge ofelectricity into a human body, and a conductor cap placed on the end ofa digit of the hands of said body to protect said digit against theobjectionable effects of corona discharge of said electricity throughsaid digit.

3. Apparatus as disclosed including means for introducing a charge ofelectricity into a human body, and a fabric cap wet in a conductingliquid and placed on the end of a digit of the hands of said body toprotect said digit against objectionable effects of corona discharge ofsaid electricity through said digit.

HENRY L. TRAN-STROM.

